Ternary Organic Solar Cell Technologies

In recent years, ternary organic solar cell technologies have emerged as a frontier for improving the performance of organic photovoltaics by incorporating three active components within a single photoactive layer. By combining two complementary donor materials with a central acceptor, or vice versa, these systems achieve a broadened absorption spectrum, enhanced charge separation and transport, and tailored energy level alignments. The third component can act as an energy relay, facilitating exciton transfer, as a morphology modulator to refine phase separation, or as a cascade energy donor to bridge energy mismatches and suppress recombination. Hierarchical nanostructures formed through controlled phase separation yield balanced charge pathways and higher fill factors, while novel additives such as two-dimensional nanosheets or graphene derivatives serve to optimise interfacial energetics and film crystallinity. Altogether, ternary blends have demonstrated power conversion efficiencies surpassing those of their binary counterparts, offering pathways to low-cost, flexible, lightweight and large-area solar modules. As the field advances, the design rules for complementary absorption, cascade energy alignment and robust morphological control promise scalable solutions for renewable energy deployment worldwide.

Research from Nature Portfolio

Recent studies have demonstrated that incorporating metal–organic framework nanosheets into a polymer-fullerene blend can serve a triple function: they enhance light absorption, align energy levels at donor-acceptor interfaces and refine film morphology. By tuning the nanosheet composition, efficiency improvements have been linked to reduced trap states and more uniform percolation pathways. Seminal work on ternary blend polymer solar cells has revealed that adding a third organic component not only broadens the absorption window but also suppresses trap-assisted recombination, elevating open-circuit voltage and fill factor. In this system, energy transfer from one donor species to another effectively funnels excitons to the optimal acceptor junction, while the third component reduces interfacial defects and boosts charge extraction, collectively driving power conversion efficiencies above 9 %.

Ternary Organic Solar Cell Technologies publication trend

The graph below shows the total number of articles in ternary organic solar cell technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Ternary blend: A photoactive layer composed of three organic semiconductors—two donors and one acceptor or vice versa—to optimise light absorption and charge processes.

Donor: A material that, upon photon absorption, donates an electron to an acceptor, generating free charges.

Acceptor: A material that accepts electrons from a donor, facilitating charge separation and transport.

Power conversion efficiency (PCE): The ratio of electrical power output to incident solar power, expressing device performance.

Phase separation: The spontaneous organisation of donor and acceptor materials into distinct nanoscale domains critical for balanced charge transport.

Energy transfer: The non-radiative transfer of excitonic energy from one material to another, improving charge generation at favourable junctions.

Fill factor (FF): A parameter quantifying the squareness of the current–voltage curve, reflecting charge transport and recombination losses.

References

1. Tuning the morphology and energy levels in organic solar cells with metal–organic framework nanosheets. Scientific Reports (2024).
2. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes. Nature Communications (2015).
3. Unraveling the Complex Nanomorphology of Ternary Organic Solar Cells with Multimodal Analytical Transmission Electron Microscopy. Solar RRL (2020).
4. Improvement of Exciton Collection and Light-Harvesting Range in Ternary Blend Polymer Solar Cells Based on Two Non-Fullerene Acceptors. Nanomaterials (2020).
5. Emphasizing the Operational Role of a Novel Graphene-Based Ink into High Performance Ternary Organic Solar Cells. Nanomaterials (2020).
6. Understanding the Impact of Hierarchical Nanostructure in Ternary Organic Solar Cells. Advanced Science (2015).